Ordering number : EN7947B
LB11948T
Monolithic Digital IC
PWM Constant Current Control 1-2
Phase Excitation Stepping Motor
Driver
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Overview
The LB11948T is a low saturation voltage output PWM current control bipolar drive stepping motor driver. It is
optimal for use as the driver for the miniature low-voltage stepping motors used in portable electronic equipment such
as portable thermal printers.
Features
• PWM current control (external excitation)
• Simultaneous on state prevention function (through current prevention)
• Thermal shutdown circuit
• Noise canceller function
• Low-power mode control pin
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter
Symbol
VS supply voltage
Conditions
Logic system supply voltage
VCC
Peak output current
IO peak
Continuous output current
Ratings
Unit
-0.3 to +18
VS
tW ≤ 20μS
V
-0.3 to +18
V
0.5
A
IO max
0.4
A
Emitter output voltage
VE
1.0
V
Input voltage
VIN
-0.3 to VCC
V
Allowable power dissipation
1.2
W
Operating temperature
Pd max
Topg
Mounted on the specified PCB*
-20 to +85
°C
Storage temperature
Tstg
-40 to +150
°C
Note * : Specified PCB : 114.3×76.1×1.6mm
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Semiconductor Components Industries, LLC, 2013
June, 2013
D2607 MS PC 20060201-S00001/N2206/D1504TN(OT)/81004TN(OT) No.7947-1/13
LB11948T
Recommended Operating Conditions at Ta = 25°C
Parameter
Symbol
VS supply voltage
Conditions
Ratings
Unit
VS
3.0 to 15
V
VCC supply voltage
VCC
3.0 to 15
V
Reference voltage
VREF
VCC ≤ 4V
0.0 to 1.0
V
VCC > 4V
0.0 to 1.5
V
Electrical Characteristics Ta = 25°C, VS = VCC = 5V, VREF = 0.3V
Parameter
Symbol
Ratings
Conditions
min
typ
Unit
max
[Output Block]
VS system supply current
IVS OFF
PH1 = PH2 = 0V, EN1 = EN2 = 3.0V, ST = 3.0V
IVS ON
PH1 = PH2 = EN1 = EN2 = 0V, ST = 3.0V
28
5
μA
40
52
mA
1
μA
Output saturation voltage 1
VO (sat) 1
IO = +0.2A (source)
0.2
0.4
V
Output saturation voltage 2
VO (sat) 2
IO = +0.4A (source)
0.3
0.5
V
Output saturation voltage 3
VO (sat) 3
IO = -0.2A (sink)
0.2
0.4
V
Output saturation voltage 4
VO (sat) 4
IO = -0.4A (sink)
0.3
0.5
V
Output leakage current
IO1 (leak)
VO = VBB (sink)
50
μA
IO2 (leak)
VO = 0V (source)
-50
IVS wt
PH1 = PH2 = EN1 = EN2 = ST = 0V
μA
Upper and lower side output diodes
Forward voltage 1 (upper side)
VF1
I = 400mA
0.9
1.1
1.3
V
Forward voltage 2 (lower side)
VF2
I = 400mA
0.9
1.1
1.3
V
ICC OFF
PH1 = PH2 = 0V, EN1 = EN2 = 3.0V, ST = 3.0V
6.5
10
13.5
mA
ICC ON
PH1 = PH2 = EN1 = EN2 = 0V, ST = 3.0V
7
11
15
mA
ICC wt
PH1 = PH2 = EN1 = EN2 = ST = 0V
1
μA
[Logic Block]
VCC system supply current
Input voltage
VI on
2.0
V
VI off
0.8
V
μA
Input current
IIN
VIN = 5V
70
100
130
Reference voltage : 1V
V1V
IO = 1mA
0.95
1
1.05
V
-22
-17
-10.5
mA
Current setting reactive current
IE
Reference current
IREF
VREF = 0.3V, VE = 0.3V
-1
CR pin current 1
ICR1
CR = 0.5V
-2
CR pin current 2
ICR2
CR = 3V
Sense voltage 1
VSEN1
Thermal shutdown temperature *
TS
1.65
VREF = 0.5V
0.475
*
μA
μA
2.2
2.75
0.5
0.525
mA
V
°C
170
Note * : Design guarantee value
Truth Table
Channel 1
Input
Channel 2
Input
Output
Input
Output
ST
PHASE1
ENABLE1
OUT1-
OUT1
PHASE2
ENABLE2
OUT2-
OUT2
H
L
L
H
L
L
L
H
L
H
H
L
L
H
H
L
L
H
H
*
H
OFF
OFF
*
H
OFF
OFF
L
*
*
OFF
OFF
*
*
OFF
OFF
Note * : Levels shown as an asterisk (*) can be set to be either high or low.
No.7947-2/13
LB11948T
Package Dimensions
unit : mm (typ)
3259
Pd max -- Ta
9.75
30
0.5
7.6
5.6
16
15
1
0.15
0.22
(1.0)
1.2max
0.65
Specified PCB : 114.3×76.1×1.6mm
PCB material : glass epoxy
1.2
1.0
0.8
0.62
0.6
0.4
0.2
0
– 20
0.08
(0.33)
Allowable power dissipation, Pd max – W
1.4
0
20
40
60
80 85
100
Ambient temperature, Ta – °C
SANYO : TSSOP30(275mil)
Pin Assignment
Top view
No.7947-3/13
LB11948T
Pin Functions
Pin No.
Pin Name
1
OUT1-
Output
Description
2
OUT1
Output
3
NC
Unused
4
NC
Unused
5
D-GND
6
E1
Lower side internal diode anode connection
Constant current control sensing
The motor current is set by the value of the sensing resistor Re connected between the E1 pin and ground.
The current is set according to the following equation : IO = VREF/Re (A)
7
VS1
8
NC
9
VCC
10
CR
11
VREF1
VS power supply
Unused
VCC power supply
RC oscillator connection
Current setting system reference voltage input
VREF1 voltage range : 0 to 0.5V
12
NC
Unused
13
ENABLE1
Output is turned on when ENABLE1 is low, and the output is turned off (operating state) when ENABLE1 is high.
14
PHASE1
Logic level input : phase switching
When PHASE1 = high : Output pin states : OUT1 : high, OUT1- : low.
When PHASE1 = low : Output pin states : OUT1 : low, OUT1- : high.
15
ST
Standby mode setting
When ST = high : the IC operates in normal operating mode.
When ST = low : the IC operates in standby mode. The VS and VCC current drain levels are under 1μA in this mode.
16
NC
17
1VREG
Unused
1V regulator circuit output
The LB11948 includes an internal 1V regulator circuit, and this pin is the output from that circuit. The VREF1 and VREF2
reference voltages can be set by voltage dividing the 1V regulator output.
18
PHASE2
Logic level input : phase switching
When PHASE2 = high : Output pin states : OUT2 : high, OUT2- : low.
When PHASE2 = low : Output pin states : OUT2 : low, OUT2- : high.
19
ENABLE2
Output is turned on when ENABLE2 is low, and the output is turned off (operating state) when ENABLE2 is high.
20
VREF2
Current setting reference voltage input
VREF2 voltage range : 0 to 0.5V
21
GND
Ground (small signal circuit system ground)
22
PGND
23
NC
Unused
24
VS2
VS power supply
25
E2
Power system ground (high current circuit system ground)
Constant current control sensing
The motor current is set by the value of the sensing resistor Re connected between the E2 pin and ground.
The current is set according to the following equation : IO = VREF/Re (A)
26
D-GND2
Lower side internal diode anode connection
27
NC
Unused
28
NC
Unused
29
OUT2
Output
30
OUT2-
Output
No.7947-4/13
LB11948T
10μF
Block Diagram
VCC
Stepping
Motor
ENABLE1
OUT1
10μF
VS1
OUT1PHASE1
E1
1Ω
Control block
+
-
ENABLE2
Blanking
time
VS2
OUT2
PHASE2
OUT2-
ST
E2
1Ω
Blanking
time
+
Reference
voltage
P-GND
OSC
CR
P-GND
VCC VREF2
VREF1
56kΩ
680pF
1VREG
10kΩ 30kΩ
S-GND
Thermal
shutdown circuit
No.7947-5/13
LB11948T
Sample Application Circuit
1 OUT1-
OUT2- 30
M
2
OUT2 29
OUT1
3 NC
NC 28
4 NC
NC 27
D-GND2 26
5 D-GND
1Ω
1Ω
E2 25
6 E1
8V
7 VS1
VS2 24
8 NC
NC 23
10μF
9 VCC
5V
56kΩ
680pF
10 CR
11 VREF1
LB11948T
10μF
12 NC
PGND 22
GND 21
VREF2 20
ENABLE2 19
Logic level input
13 ENABLE1
Logic level input
PHASE2 18
30kΩ 10kΩ
14 PHASE1
15 ST
Logic level input
1VREG 17
16
90 deg
PHASE1
PHASE2
200 Hz
No.7947-6/13
LB11948T
Drive Sequence Table
2 Phase Excitation Drive Sequence
Table 1 Clockwise drive
No.
PHASE1
ENABLE1
OUT1
OUT1-
PHASE2
ENABLE2
OUT2
OUT2-
0
0
0
0
1
0
0
0
1
1
1
0
1
0
0
0
0
1
2
1
0
1
0
1
0
1
0
3
0
0
0
1
1
0
1
0
No.
PHASE1
ENABLE1
OUT1
OUT1-
PHASE2
ENABLE2
OUT2
OUT2-
0
0
0
0
1
1
0
1
0
1
1
0
1
0
1
0
1
0
2
1
0
1
0
0
0
0
1
3
0
0
0
1
0
0
0
1
Table 2 Counterclockwise drive
1-2 Phase Excitation Drive Sequence
Table 3 Clockwise drive
No.
PHASE1
ENABLE1
OUT1
OUT1-
PHASE2
ENABLE2
OUT2
OUT2-
0
0
0
0
1
0
1
OFF
OFF
1
0
0
0
1
0
0
0
1
2
1
1
OFF
OFF
0
0
0
1
3
1
0
1
0
0
0
0
1
4
1
0
1
0
1
1
OFF
OFF
5
1
0
1
0
1
0
1
0
6
0
1
OFF
OFF
1
0
1
0
7
0
0
0
1
1
0
1
0
No.
PHASE1
ENABLE1
OUT1
OUT1-
PHASE2
ENABLE2
OUT2
OUT2-
0
0
0
0
1
1
1
OFF
OFF
0
Table 4 Counterclockwise drive
1
0
0
0
1
1
0
1
2
1
1
OFF
OFF
1
0
1
0
3
1
0
1
0
1
0
1
0
4
1
0
1
0
0
1
OFF
OFF
5
1
0
1
0
0
0
0
1
6
0
1
OFF
OFF
0
0
0
1
7
0
0
0
1
0
0
0
1
No.7947-7/13
LB11948T
2 Phase Excitation Drive Sequence
Clockwise drive
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
PHASE1
PHASE2
ENABLE1
ENABLE2
OUT1
OUT1-
OUT2
OUT2-
Counterclockwise drive
PHASE1
PHASE2
ENABLE1
ENABLE2
OUT1
OUT1-
OUT2
OUT2-
No.7947-8/13
LB11948T
1-2 Phase Excitation Drive Sequence
Clockwise drive
0
1
2
3
4
5
6
7
2
3
4
5
6
7
PHASE1
PHASE2
ENABLE1
ENABLE2
OUT1
OUT1-
OUT2
OUT2-
: Output off state
Clockwise drive
0
1
PHASE1
PHASE2
ENABLE1
ENABLE2
OUT1
OUT1-
OUT2
OUT2-
: Output off state
No.7947-9/13
LB11948T
Switching Operation Timing Chart
OUTA
OUTA
IO
Spike noise
E1
CR
tn
tn: The noise canceller operating time
No.7947-10/13
LB11948T
Usage Notes
(1) Simple Formulas for Determining Resister and Capacitor Values
The formula for setting the rising time (T1) and the falling time (T2) for the RC oscillator are shown below. (Refer to
Fig. 1)
T2
V2
V1
T1
Fig. 1
Formulas
Oscillation period T = T1+T2 (sec)
Threshold voltages V1 = ((VCC - Vset1) × 10.7k/48.7k) + Vset1 (V)
V2 = ((VCC - Vset2) × 42.7k/80.7k) + Vset2 (V)
Vset1 : VCE voltage of transistor for internal comparator hysteresis = 0.05V
Vset2 : VCE voltage of reference resistance switching transistor of oscillation circuit = 0.1V
When charging :
T1 = -C × R × ln {(VCC - V2)/(VCC - V1)} (sec)
When discharging : T2 = -C × Rin × ln (V1/V2) (sec)
Rin : Internal discharge resistance of the CR pin1.3kΩ
C : External capacitor
R : External resistor
Oscillation frequency
Fc = 1/T (Hz)
The T2 fall time serves as the noise canceling time (Tn). This time is a forced-on time for the output, and the output is
not turned off even when the E pin voltage is higher than the sense voltage that has been preset by VREF.
No.7947-11/13
LB11948T
(2) Constant current settings
The reference voltages of the VREF1 and VREF2 pins can be set by dividing the resistance voltage from the 1V
regulator output pin (1VREG).
The output current is set using the VREF reference voltage applied to the VREF1 and VREF2 pins and the Re resistor
connected between the E1 and E2 pins and ground. The bias current of the output transistor also flows from the E pins
so that the Iout output current flowing to the motor is reduced by an amount equivalent to the bias current. In addition,
in controlling the constant current, the voltage is sensed by the E pins (pad area on IC chip) so that the amount
equivalent to the wire bonding resistance (rw) from the pad to the package pins is added to the current sensing
resistance (Re).
Therefore, the formula for calculating the current setting is as shown below. (Refer to Fig. 2)
IOUT = VREF / (Re + rw) - Ibias
[A]
Re : Sensing resistance of resistor connected between E pins and ground
rw : Amount equivalent to wire bonding resistance from pad to pins rw = 50 - 100mΩ
Ibias : Output transistor bias current
The Ibias current corresponds to the current setting reactive current (IE) in the specifications for the electrical
characteristics.
Current setting reactive current IE ratings : Min : -22mA Typ : -17mA Max : -10.5mA
IO
Ibias
Sense current : Ie = IO+Ibias
Wire (rw)
IC E1 pin
Re
VREF
IC VREF1 pin
Fig. 2
(3) VREF pins
The VREF pins are the reference voltage input pins for the preset current, so take special care to ensure that they are
not affected by noise. If these pins will be affected by noise, connect a capacitor to VREF1 and VREF2 pins.
(4) Notes on the Ground Pins
Since this IC switches large currents, the following notes on ground lines must be observed.
• The PCB pattern lines in areas that handle large currents must be as wide as possible so as to have low impedances,
and must be kept as far as possible from the small signal systems.
• The ground terminals on the sensing resistors Re connected to the E pins (E1 and E2) must be connected as close as
possible to the IC GND (pin 21), PGND (pin 22), or DGND (pins 5 and 26) pins as possible.
• The capacitors between VCC and ground and between VBB and ground must be as close as possible to the
corresponding VCC and VBB pin in the pattern.
No.7947-12/13
LB11948T
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PS No.7947-13/13